1967 HO has the exhaust manifold with the flapper. When I had the engine rebuilt we took off the flapper and welded the holes on the exhaust manifold. Does the carb choke have any connection to the exhaust manifold. Would the exhaust manifold flapper door have any connection to the carb idle-choke? The reason I ask, I have 2 carbs, a rebuilt qjet with electric choke that is on the car now and the original one(manual choke) that I was told wasn't any good. I'm thinking the right carb guy could rebuild it. It was on the car originally before but the idle had to be set so high or it would stall and until it was warmed up it would just die out and I had to keep pumping the gas peddle to keep it from stalling out at a stop light. In fact I had to put it in nuetral at every light just so I wouln't stall out. The mechanic could not get the carb adjusted so I think he just gave up and said get a new one by default and I listened to him. So I got the rebuilt qjet one that would bolt right on with the original linkage and minimal down time and an electric choke. But this carb has issues too, the idle has to be set so high to keep it running at a stop light. The car runs fantastic in all other respects. Great acceleration, high way cruising speed and kick down. Its just the idle speed. The original carb is numbers matching date code correct carb! So now after a long winter here in Minnesota and having plenty of time to think about this, I'm thinking of rebuilding the original carb. The mechanic says bring the (rebuilt ) to the shop you bought it at, I did and he said find a competent mechanic. Help!